Efficiency, Concentration and Competition in the Turkish Banking Sector

Yapı-Davranış-Performans (YDP) yaklaşımı i&ccedil;inde yer alan işbirliği hipotezineg&ouml;re yoğunlaşma ile rekabet arasında negatif bir ilişki mevcuttur. Etkin yapı hipoteziise etkinlik ile rekabet arasında pozitif bir ilişkiyi ileri s&uuml;rer. Bu yaklaşımlardan her ikiside piyasalarda yoğunlaşma ile rekabetin aynı anda bir arada bulunamayacağını ifadeederler. Son d&ouml;nemde, yeni ampirik end&uuml;stri iktisadı (YAEİ) yaklaşımı yoğunlaşmanıny&uuml;ksek olduğu piyasalarda bile rekabet&ccedil;i bir yapının olabileceğini kanıtlamıştır. Buyaklaşımlarda yoğunlaşma, etkinlik ve rekabet arasındaki ilişki teorik d&uuml;zeyde a&ccedil;ıklanmış,bu değişkenler arasındaki ilişkinin y&ouml;n&uuml; ise ampirik bir soru olarak belirmiştir. İşte bu&ccedil;alışmada 1990-2011 d&ouml;neminde T&uuml;rk bankacılık sekt&ouml;r&uuml;nde etkinlik, yoğunlaşma verekabet arasındaki ilişki Panzar-Rosse (1987) ve Veri Zarflama Analizi (VZA) ile testedilmiştir. YDP yaklaşımının aksine bu &ccedil;alışmada, T&uuml;rk bankacılık sekt&ouml;r&uuml;nde s&ouml;z konusud&ouml;nemde rekabet arttık&ccedil;a piyasada etkinlik d&uuml;zeyinin de arttığı belirlenmiştirThe collusion hypothesis in the Structure-Conduct-Performance (SCP) approach assumesa negative relationship between concentration and competition. The efficient structurehypothesis asserts a positive relationship between efficiency and competition. Bothof these traditional approaches to industrial economics imply that markets cannot besimultaneously concentrated and competitive. Recently, the new empirical industrialeconomics (NEIO) approach proved that competition may exist in markets even whenconcentration is high. Although the links among competition, concentration and efficiencyhave been established by these approaches at a theoretical level, the direction of causalityamong these variables remains as an empirical question to be addressed. Thus, thisstudy aims to empirically explore the direction of the relationship among concentration,efficiency and competition employing the Panzar and Rosse (1987) model and DataEnvelopment Analysis (DEA) methods to the Turkish banking sector over the period of1990-2011. Contrary to the predictions of the SCP approach, the findings of this studyreveal that the level of efficiency increases in the sector as long as the level of competitionincreases in the market.</p

Actinomycosis in concha bullosa: a case report

Actinomyces, a gram-positive, anaerobic-to-microaerophilic species of bacteria, lives as commensal in human body. In this report, actinomycosis in concha bullosa in a 51-year-old woman is presented and it is aimed to add a case to the very rarely reported atypical locations of actinomycosis. Also, diagnostic and therapeutic approaches were discussed. Actinomycosis should also be considered in the differential diagnosis of the patients with effluent at head and neck region and nasal cavity in daily practice of otorhinolaryngology